The deviation of flow characteristics from the predictions of the conventional theory for microtubes was attrib- uted to the change of fluid viscosity resulted from the interactions between the molecules on solid wall...The deviation of flow characteristics from the predictions of the conventional theory for microtubes was attrib- uted to the change of fluid viscosity resulted from the interactions between the molecules on solid wall and in fluid. The degree of this departure is dependent on the microtubes materials. A concept of equivalent thickness with which conventional theory can be used to predict the flow in microtubes without modifying the fluid viscosity was put forward. The values of equivalent thickness for fused silica and stainless steel materials were determined as 1.8 μm and 1.5 μm, respectively, by repeated numeri- cal simulation.展开更多
Ionic liquids analogues known as Deep Eutectic Solvents （DESs） are gaining a surge of interest by the scientific community, and many applications involving DESs have been realized. Moisture content is one of the imp...Ionic liquids analogues known as Deep Eutectic Solvents （DESs） are gaining a surge of interest by the scientific community, and many applications involving DESs have been realized. Moisture content is one of the important factors that affects the physical and chemical characteristics of these fluids. In this work, the effect of mixing water with three common type III DESs on their viscosity was investigated within the water tool fraction range of （0-1） and at the temperature range （298.15-353.15 K）. Similar trends of viscosity variation with respect to molar composition and temperature were observed for the three studied systems, Due to the asymmetric geometry of the constituting molecules in these fluids, their viscosity could not be modeled effectively by the conventional Grunberg and Nissan model, and the Fang-He model was used to address this issue with excellent performance. All studied aqueous DES mixtures showed negative deviation in viscosity as compared to ideal mixtures, The degree of intermolecular interactions with water reaches a maximum at a composition of 30% aqueous DES solution. Reline, the most studied DES in the literature, showed the highest deviation. The informa- tion presented in this work on the viscosity of aqueous DES solutions may serve in tuning this important property for diverse industrial applications involving these novel fluids in fluid flow, chemical reactions, liquid-liquid separation and many more.展开更多
Abstract： Mechanical properties of clay under high stress are quite different from those under low stress. It is necessary to investi- gate unloading properties of clay under high stress for the design and constructi...Abstract： Mechanical properties of clay under high stress are quite different from those under low stress. It is necessary to investi- gate unloading properties of clay under high stress for the design and construction of deep underground engineering projects. A series of experiments were conducted to investigate the unloading properties of clay under high confining pressures by using a SKA-1 high pressure consolidation instrument designed by us. The stress versus strain relationship and the way that K0 values of clay change during the loading-unloading process were discovered. The results show that there are clear differences in the state of stress and deformation behavior of the clay along different unloading paths.展开更多
The rheological properties of most liquid in nature are between liquids and solids, including both elastic changes and viscosity changes, that is socalled ＂viscoelastic＂. Dynamic oscillatory test was used to quantit...The rheological properties of most liquid in nature are between liquids and solids, including both elastic changes and viscosity changes, that is socalled ＂viscoelastic＂. Dynamic oscillatory test was used to quantitatively study the distinct viscoelastic behaviors of debris flow slurry in the shear stress conditions for the first time in this study. The debris flow slurry samples were from Jiangjiagou Ravine, Yunnan Province, China. The experimental results were found that at the low and middle stages of shearing, when the angular velocity 09〈72.46 s-1, the loss modulus （G was greater than the storage modulus （G3, i.e. G＂〉G＇. At the late stage of shearing, when the angular velocity co-72.46 s-x, the storage modulus was greater than or equal to the loss G = G, tan -〈 1 （where phase-shift modulus, i.e. ＇ 〉 ＂ angle 5=G＂,/G3, and the debris flow slurry was in a gel state. Therefore, the progress of this experimental study further reveals the mechanism of hyperconcentrated debris flows with a high velocity on low-gradient ravines.展开更多
China clay was employed as an adsorbent for the removal of Mg 2+ from water at pH 7.0 within the temperature range of 303～328 K. The linearity of the plots indicated Langmuir type isotherms. The reaction was ex...China clay was employed as an adsorbent for the removal of Mg 2+ from water at pH 7.0 within the temperature range of 303～328 K. The linearity of the plots indicated Langmuir type isotherms. The reaction was exothermic. A maximum removal of 35% was obtained at 0.50 mmol L -1 metal concentration and a pH of 7.0 at 303 K. The H + rel /Mg 2+ ads ratio changed from a fractional value to 2.5. Strong chemical bondings took place between oxygen atom of the surface and Mg 2+ , resulting in a surface complex species. Temperature had a significant effect on H + rel , and the stability constants also increased with increasing temperature.展开更多
Toxicological studies on an adhesive blocking agent for vas deferens were carried out.It could be excreted from the body soon after some of the agent had been absorbed. No long-term accumulation phenomenon and no obvi...Toxicological studies on an adhesive blocking agent for vas deferens were carried out.It could be excreted from the body soon after some of the agent had been absorbed. No long-term accumulation phenomenon and no obvious effect of acute toxicity on rodent animals have been observed. The parameters of physiology, blood cells and blood biochemistry were not affected apparently. The histomorphological study showed that the blocked part of vas deferens was obliterated with fibrous tissue and sperm deposition was found in the blocked end toward epididymis. The agent had no carcinogenic effect. Moreover, on the basis of mutation assay with Salmonella typhimarium strains, analysis of chromosome aberration, mieronuclei assay in bone marrow cells of mouse and domirrant lethal mutation assay, it was shown that the agent had no mutagenic effect.展开更多
We study the vanishing viscosity of the Navier-Stokes equations for interacting shocks. Given an entropy solution to p-system which consists of two different families of shocks interacting at some positive time,we sho...We study the vanishing viscosity of the Navier-Stokes equations for interacting shocks. Given an entropy solution to p-system which consists of two different families of shocks interacting at some positive time,we show that such entropy solution is the vanishing viscosity limit of a family of global smooth solutions to the isentropic Navier-Stokes equations. The key point of the proofs is to derive the estimates separately before and after the interaction time and connect the incoming and outgoing viscous shock profiles.展开更多
OBJECTIVE: To study the adhesion, migration and three-dimentional growth of Schwann cells on PLA (polylactic acid) nonspinning fibre cloth and polyglycolic/polylactic acid (PLGA) fibres. METHODS: Schwann cells/ECM gel...OBJECTIVE: To study the adhesion, migration and three-dimentional growth of Schwann cells on PLA (polylactic acid) nonspinning fibre cloth and polyglycolic/polylactic acid (PLGA) fibres. METHODS: Schwann cells/ECM gel solution and PLA nonspinning fibre cloth and PLGA fibres pretreated by collagen, polylysine and ECM were co-cultured. Then the migration and three-dimensional growth of Schwann cells on the fibres were observed under phase contrast microscope and laser scanning confocal microscope. RESULTS: Schwann cell/ECM solution was compounded with PLA nonspinning fibre cloth. With formation of gel, most Schwann cells resided in the fibre net holes, and adhered to the fibres to form a multiplayer-arranged Schwann cell column like Bungner band. Schwann cells could adhere to PLGA fibres and grew and migrated along the fibres. ECM gel could significantly increase the adhering and migrating cell number. CONCLUSIONS: ECM gel can facilitate the adhesion, growth and migration of Schwann cells on the seteroframe. It is a good integrating material for tissue engineering bioartificial nerve.展开更多
Based on the immersed boundary method,a fast simulation for solving unsteady,incompressible,viscous flow associated with the oscillating cascade is established on a quasi-three-dimensional coordinate system.The numeri...Based on the immersed boundary method,a fast simulation for solving unsteady,incompressible,viscous flow associated with the oscillating cascade is established on a quasi-three-dimensional coordinate system.The numerical method is applied to the simulation of the flow passing an oscillating circular cylinder which is forced to move in X direction under prescribed motions in water at rest at low Keulegan-Carpenter numbers.Then vor-tex-induced vibration of a cylinder with two degrees of freedom which oscillates in in-line direction and transverse direction is simulated using this method.The results are in good agreement with the previous research.Then the method is extended to the oscillating cascade simulation of making various comparisons.It is found that the IBPA(inter blade phase angle) will change as the time goes on,because of the non-uniformity of the flow in the circumferential direction,until the oscillating cascade goes to a stable situation.The reduced velocity and the number of blades are chosen to investigate the effects of them on IBPA.The results indicate that both the reduced velocity and the number of blades are the main factors which influence IBPA.It is worth noting that the coupling process is not necessary to generate any body-fitting grids,which makes it much faster in computational process for such a complicated fluid-structure interaction problem.展开更多
Mathematical model is developed for peristaltic flow of viscous fluid through a compliant wall channel subject to melting heat transfer. Fluid is incompressible and magnetohy- drodynamic. Analysis has been performed i...Mathematical model is developed for peristaltic flow of viscous fluid through a compliant wall channel subject to melting heat transfer. Fluid is incompressible and magnetohy- drodynamic. Analysis has been performed in the presence of Joule heating and thermal radiation. Solutions for small wave number are obtained. Physical quantities of interest are examined for various parameters of interest.展开更多
基金Project (No. 20299030) supported by the National Natural ScienceFoundation of China
文摘The deviation of flow characteristics from the predictions of the conventional theory for microtubes was attrib- uted to the change of fluid viscosity resulted from the interactions between the molecules on solid wall and in fluid. The degree of this departure is dependent on the microtubes materials. A concept of equivalent thickness with which conventional theory can be used to predict the flow in microtubes without modifying the fluid viscosity was put forward. The values of equivalent thickness for fused silica and stainless steel materials were determined as 1.8 μm and 1.5 μm, respectively, by repeated numeri- cal simulation.
文摘Ionic liquids analogues known as Deep Eutectic Solvents （DESs） are gaining a surge of interest by the scientific community, and many applications involving DESs have been realized. Moisture content is one of the important factors that affects the physical and chemical characteristics of these fluids. In this work, the effect of mixing water with three common type III DESs on their viscosity was investigated within the water tool fraction range of （0-1） and at the temperature range （298.15-353.15 K）. Similar trends of viscosity variation with respect to molar composition and temperature were observed for the three studied systems, Due to the asymmetric geometry of the constituting molecules in these fluids, their viscosity could not be modeled effectively by the conventional Grunberg and Nissan model, and the Fang-He model was used to address this issue with excellent performance. All studied aqueous DES mixtures showed negative deviation in viscosity as compared to ideal mixtures, The degree of intermolecular interactions with water reaches a maximum at a composition of 30% aqueous DES solution. Reline, the most studied DES in the literature, showed the highest deviation. The informa- tion presented in this work on the viscosity of aqueous DES solutions may serve in tuning this important property for diverse industrial applications involving these novel fluids in fluid flow, chemical reactions, liquid-liquid separation and many more.
基金Project 50534040 supported by the National Natural Science Foundation of China
文摘Abstract： Mechanical properties of clay under high stress are quite different from those under low stress. It is necessary to investi- gate unloading properties of clay under high stress for the design and construction of deep underground engineering projects. A series of experiments were conducted to investigate the unloading properties of clay under high confining pressures by using a SKA-1 high pressure consolidation instrument designed by us. The stress versus strain relationship and the way that K0 values of clay change during the loading-unloading process were discovered. The results show that there are clear differences in the state of stress and deformation behavior of the clay along different unloading paths.
基金supported by the Youth Talent Team Program of Institute of Mountain Hazards and Environment,CASthe National Natural Science Foundation of China (Grant No.406710260)
文摘The rheological properties of most liquid in nature are between liquids and solids, including both elastic changes and viscosity changes, that is socalled ＂viscoelastic＂. Dynamic oscillatory test was used to quantitatively study the distinct viscoelastic behaviors of debris flow slurry in the shear stress conditions for the first time in this study. The debris flow slurry samples were from Jiangjiagou Ravine, Yunnan Province, China. The experimental results were found that at the low and middle stages of shearing, when the angular velocity 09〈72.46 s-1, the loss modulus （G was greater than the storage modulus （G3, i.e. G＂〉G＇. At the late stage of shearing, when the angular velocity co-72.46 s-x, the storage modulus was greater than or equal to the loss G = G, tan -〈 1 （where phase-shift modulus, i.e. ＇ 〉 ＂ angle 5=G＂,/G3, and the debris flow slurry was in a gel state. Therefore, the progress of this experimental study further reveals the mechanism of hyperconcentrated debris flows with a high velocity on low-gradient ravines.
文摘China clay was employed as an adsorbent for the removal of Mg 2+ from water at pH 7.0 within the temperature range of 303～328 K. The linearity of the plots indicated Langmuir type isotherms. The reaction was exothermic. A maximum removal of 35% was obtained at 0.50 mmol L -1 metal concentration and a pH of 7.0 at 303 K. The H + rel /Mg 2+ ads ratio changed from a fractional value to 2.5. Strong chemical bondings took place between oxygen atom of the surface and Mg 2+ , resulting in a surface complex species. Temperature had a significant effect on H + rel , and the stability constants also increased with increasing temperature.
文摘Toxicological studies on an adhesive blocking agent for vas deferens were carried out.It could be excreted from the body soon after some of the agent had been absorbed. No long-term accumulation phenomenon and no obvious effect of acute toxicity on rodent animals have been observed. The parameters of physiology, blood cells and blood biochemistry were not affected apparently. The histomorphological study showed that the blocked part of vas deferens was obliterated with fibrous tissue and sperm deposition was found in the blocked end toward epididymis. The agent had no carcinogenic effect. Moreover, on the basis of mutation assay with Salmonella typhimarium strains, analysis of chromosome aberration, mieronuclei assay in bone marrow cells of mouse and domirrant lethal mutation assay, it was shown that the agent had no mutagenic effect.
基金supported by National Basic Research Program of China(973 Program)(Grant No.2011CB808002)the National Center for Mathematics and Interdisciplinary Sciences,Academy of Mathematics and Systems Science,Chinese Academy of Sciences and the Chinese Academy of Sciences Program for Cross&Cooperative Team of the Science&Technology Innovation,National Natural Sciences Foundation of China(Grant Nos.11171326,11371064 and 11401565)the General Research Fund of Hong Kong(Grant No.City U 103412)
文摘We study the vanishing viscosity of the Navier-Stokes equations for interacting shocks. Given an entropy solution to p-system which consists of two different families of shocks interacting at some positive time,we show that such entropy solution is the vanishing viscosity limit of a family of global smooth solutions to the isentropic Navier-Stokes equations. The key point of the proofs is to derive the estimates separately before and after the interaction time and connect the incoming and outgoing viscous shock profiles.
基金This study was supported by the National Natural Science Foundation of China(No.30100190)
文摘OBJECTIVE: To study the adhesion, migration and three-dimentional growth of Schwann cells on PLA (polylactic acid) nonspinning fibre cloth and polyglycolic/polylactic acid (PLGA) fibres. METHODS: Schwann cells/ECM gel solution and PLA nonspinning fibre cloth and PLGA fibres pretreated by collagen, polylysine and ECM were co-cultured. Then the migration and three-dimensional growth of Schwann cells on the fibres were observed under phase contrast microscope and laser scanning confocal microscope. RESULTS: Schwann cell/ECM solution was compounded with PLA nonspinning fibre cloth. With formation of gel, most Schwann cells resided in the fibre net holes, and adhered to the fibres to form a multiplayer-arranged Schwann cell column like Bungner band. Schwann cells could adhere to PLGA fibres and grew and migrated along the fibres. ECM gel could significantly increase the adhering and migrating cell number. CONCLUSIONS: ECM gel can facilitate the adhesion, growth and migration of Schwann cells on the seteroframe. It is a good integrating material for tissue engineering bioartificial nerve.
文摘Based on the immersed boundary method,a fast simulation for solving unsteady,incompressible,viscous flow associated with the oscillating cascade is established on a quasi-three-dimensional coordinate system.The numerical method is applied to the simulation of the flow passing an oscillating circular cylinder which is forced to move in X direction under prescribed motions in water at rest at low Keulegan-Carpenter numbers.Then vor-tex-induced vibration of a cylinder with two degrees of freedom which oscillates in in-line direction and transverse direction is simulated using this method.The results are in good agreement with the previous research.Then the method is extended to the oscillating cascade simulation of making various comparisons.It is found that the IBPA(inter blade phase angle) will change as the time goes on,because of the non-uniformity of the flow in the circumferential direction,until the oscillating cascade goes to a stable situation.The reduced velocity and the number of blades are chosen to investigate the effects of them on IBPA.The results indicate that both the reduced velocity and the number of blades are the main factors which influence IBPA.It is worth noting that the coupling process is not necessary to generate any body-fitting grids,which makes it much faster in computational process for such a complicated fluid-structure interaction problem.
文摘Mathematical model is developed for peristaltic flow of viscous fluid through a compliant wall channel subject to melting heat transfer. Fluid is incompressible and magnetohy- drodynamic. Analysis has been performed in the presence of Joule heating and thermal radiation. Solutions for small wave number are obtained. Physical quantities of interest are examined for various parameters of interest.
